Cost-effectiveness in dental health: a review of strategies available for preventing caries

Most decisions in public health are based on imperfect information, and this is certainly the case for dental health. Relatively little is known about the cost-effectiveness of the various options available to improve dental status. It is, however, well recognised that regular exposure to fluoride reduces the incidence of caries considerably, and it is no coincidence that oral status throughout the world has improved considerably since the widespread introduction of fluoridated toothpaste in the 1970s. Dental status is usually measured by dmft and DMFT scores, which indicate the number of decayed, missing and filled teeth in the primary and secondary dentitions at various ages. The World Health Organisation set a target in 1980 of an average DMFT score of 3 or less for 12 year olds by the year 2000. The target has already been achieved by the population as a whole. However, despite the recent improvements in the oral status of Britain’s children, between 10% and 20% suffer from poor dental health and are regarded as an at-risk group. These children tend to be concentrated geographically in certain parts of Britain, and poor oral status is often associated with poverty and socio-economic deprivation. This paper explores a number of strategies available for preventing caries. Although caries is seldom life-threatening, it causes unnecessary distress to a minority of the population, many of whom live in deprived inner city areas. Oral health currently represents an appreciable drain on NHS resources, accounting for 4% of total NHS expenditure per year. In order to affect an improvement in overall dental health, represented by average figures for the whole population, policies need to be targeted towards those most at risk of poor oral status. Two of the possible approaches – promoting improved self-administered oral hygiene and encouraging people to make better use of the general dental service – require people to change their behaviour. Health promotion campaigns requiring behavioural change suggest that it can be very expensive to get the message to those most at risk, and even then there is no guarantee that they will change their behaviour in the desired manner. Furthermore, both approaches suggested above have some financial consequences for the individuals, and those children most at risk of caries often come from families who can ill-afford additional financial burdens. Thus neither strategy is particularly cost-effective, and lack of compliance is a major concern. Reducing sugar consumption through dietary change is often promoted as a strategy to improve dental health, but the supporting evidence is very weak. Links between diet and oral status are complex, and many countries have reduced their dmft and DMFT scores in recent years against a background of stable or even rising sugar consumption. Much of this improvement in oral status is considered to be due to increased exposure to fluoride during this period. Dietary change can be very difficult to effect, especially given the pleasure associated with the consumption of sugar-containing foods. There is also a risk that the proportion of fat in the diet will increase if sugar consumption is reduced, especially amongst adolescents, and this may have an adverse impact on the prevalence of coronary heart disease in the near future. Water fluoridation has reduced caries levels by about 50% in those parts of the world where it has been introduced, and children living in those areas of Britain with fluoridated water consistently enjoy significantly better dental health than children living in similar areas with non-fluoridated water. Water fluoridation is extremely cost-effective, requires no user compliance, and also benefits adults by reducing root caries. However, proposals to introduce it in a number of areas in Britain have encountered strong opposition on the grounds of unproven health risks and dislike of mass medication. It may be possible to a certain extent to target water fluoridation towards the at-risk groups by only fluoridating selected treatment works, such as those serving inner city areas. The community dental service also has an important role to play in improving the oral status of the at-risk groups, since it provides dental services in schools and other local facilities. Prophylactic figure sealants are a proven way of reducing pit and fissure decay. Fluoride has the least effect upon these surfaces. And sealants are a cost-effective way of protecting these surfaces for at-risk children. The majority of children enjoy good oral health status which will be maintained by self-administered oral hygiene and regular contact with the general dental service. However, those with poor oral status often come from families who are unlikely, or even unable, to respond to campaigns to brush their teeth and visit their dentist regularly. Reducing population sugar intake through dietary change, assuming such change can occur, is unlikely to influence dental status, and may adversely affect fat consumption. Increased exposure to fluoride via selectively fluoridated water, combined with fissure sealants and regular contact with the community dental service, are the most cost-effective ways of improving the nation’s oral status.